[gnome-shell] extensions-app: Fix Logout call

[Florian Müllner <fmuellner src gnome org>]

commit 27774582b647522be6c7b30592feb51e8c2163c7
Author: Florian Müllner <fmuellner gnome org>
Date:   Sat May 2 23:32:04 2020 +0200

    extensions-app: Fix Logout call
    
    Commit 764527c8c9b adjusted the "call" call to promisification that
    never happened (in this bit of code).
    
    We can either add back a callback or properly promisify the call;
    this opts for the latter.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/2735

 subprojects/extensions-app/js/main.js | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/subprojects/extensions-app/js/main.js b/subprojects/extensions-app/js/main.js
index 382637c742..005d1ddc65 100644
--- a/subprojects/extensions-app/js/main.js
+++ b/subprojects/extensions-app/js/main.js
@@ -15,6 +15,7 @@ const { ExtensionState, ExtensionType } = ExtensionUtils;
 const GnomeShellIface = loadInterfaceXML('org.gnome.Shell.Extensions');
 const GnomeShellProxy = Gio.DBusProxy.makeProxyWrapper(GnomeShellIface);
 
+Gio._promisify(Gio.DBusConnection.prototype, 'call', 'call_finish');
 Gio._promisify(Shew.WindowExporter.prototype, 'export', 'export_finish');
 
 function loadInterfaceXML(iface) {